There are things that when you are used to it, it just doesn't "taste" as bad as others experience it.

To you and me, we associate smoking with health problems so subconsciously we hate it a lot. We also never feel the "good parts" of smoking so our minds are entirely biased into the negative aspects of it. Meanwhile, a smoker grew up without caring about the health damages and they consider it fine to smoke and the cost is acceptable for the "good" a cigarette can provide.

In a way, this is similar to how I eat some very unhealthy foods a few times a week. They taste good but to some people those things are smelly and unappetizing and definitely too much oil and cholesterol in them to be called a balanced meal. I still eat them because to me, they taste good and I am willing to trade a bit of my health for that kind of enjoyment.